Structure and electrical properties of double perovskite Sr(Ni_(1/2)Mo_(1/2))O_3 ceramics

摘要

The double perovskite Sr(Ni_(1/2)Mo_(1/2))O_3 has been prepared with solid-state reaction and was characterized by x-ray diffraction technique. It has been indicated that the single phase is formed at 1300 ℃ in air. The compound undergoes a phase transition at 280 ℃, where the structure of the ordered perovskite type changes from tetragonal (I4/m) to cubic (Fm3m). Dielectric constant (ε_γ) and dielectric loss (tan δ) are observed at the transition point. The conductivity of the sample has been studied, and the slope of dc conductivity versus the inverse of temperature corresponds to an Arrhenius activation energy in the range of 0.34-0.46 eV. This range of activation is nearly double ionized oxygen vacancies V_O in the resistivity transition of other perovskite oxides.